The present invention relates to an optical recording and reproducing apparatus which is adapted to record the information on a disc-shaped recording medium (disc) capable of recording, reproducing operations to reproduce the recorded information from this disc.
FIG. 3 shows the construction view of the conventional optical recording and reproducing apparatus. In the drawings, the optical disc 1 is rotated by the disc motor 20. The lights coming from the light source 21 of the semiconductor or the like are collected by the collimator lens 22 and are focused into the light spot of about .mu.m .phi.on the optical disc 1 by the focus lens 23. The reflection lights coming from the optical disc 1 are separated by the .lambda./4 plate 24 and the polaroid beam splitter 25 and are guided into the two-division photo detector 26. The photo detector 26 is placed so that the division line becomes parallel to the track on the optical disc 1. The tracking error signal 27 of the two-division photo detector 26 drives the focus lens 23 in the right-angled direction to the track through the tracking jumping control circuit 28 with the tracking control being applied upon it. Also, the reproducing signal output 29 is used in the reproduction of the record signal and the reproduction of the truck address. The light source 21 of the semiconductor laser or the like is set on the reproduction power or the record power by the driving circuit 30. The record signal such as the digital signal, the video signal or the like is generated by the recording signal generating circuit 31 to modulate the power of the semiconductor laser during the recording operation.
FIG. 4 shows the signal waveforms of each portion in a case where the track skipping has been caused. The b through e in FIG. 3 are the observation points of the signal waveforms b through e of FIG. 4. The a shows the track sectional view in the scanning direction of the light beam, which is a view seen from the light beam. Reference numeral 40 shows the groove track, indicating its level. Reference numeral 41 shows the flat portion between the grooves, indicating its level. Reference numeral 3 shows the track which is being recorded with the black portion shows the photographic portion. When the track skipping 8 is caused, it crosses the tracks of 4A, 4B to show that the tracking servo is applied upon the jumped track 5. FIG. 4(b) shows the output waveform of the tracking error signal 27, which becomes the track crossing signal (27A, 27B). When the tracking servo is applied upon groove track 40, the level of the error signal naturally becomes near the zero as shown in FIG. 4(b). If the falling edge of the waveforms of 27A, that is, the moment the tracking is disengaged from the track 3 which is being recorded, the track skipping 8 may be detected without the scanning operation of the record beam upon the other track. When the waveforms of the error signal 27 of FIG. 4(b) are outputted through comparison at the threshold value of 42 in the positive comparator 32 (FIG. 3), and at the threshold value of 43 in the negative comparator 33 (FIG. 3), the track skip detecting signals 44, 45 of FIG. 4(c) and (d) are provided.
In FIG. 3, the track skipping pulse signals of FIG. 4(c) and 4(d) are provided to an OR gate 34. And the flip-flop 35 is set by the output to open the analog gate 36 to break the recording signal generating circuit 31 and the semiconductor laser driving circuit 30 and to reduce from the record power to the reproduction power the optical power of the semiconductor laser driving circuit 30. FIG. 4(e) shows the light output waveforms of the semiconductor laser.
However, in such construction as described hereinabove, the track skipping cannot be correctly detected when the setting of the threshold value of the comparators 32, 33 is correct, the input level of the track crossing signal becomes smaller than at the initial setting time. Thus, it is impossible to completely prevent the error record, the double record. Also, the error record, the double record cannot be completely prevented, because the controlling operation for switching from the record power to the reproduction power cannot be effected even when the digital circuits 34, 35, 36 constituting the write protecting function break down.
As object of the present invention is to provide an optical recording and reproducing apparatus which is capable of positively preventing the error record, the double record through the diagnosis of the track skip detection, the write protecting means.
The abnormal condition wherein the photopower is not the recording power in level during the recording operation.
It is important to known whether or not the information is positively recorded in a disc in the optical recording and reproducing apparatus. Thus, when the information is on record in the disc, it is required that the photopower from the optical head should become the recording power. When the optical power is not the recording power of the object, the recording operation is immediately suspended to notify the user of it, so that the user data are protected through the abortion process. The above-described operation will be described with reference to the following drawings. A recording means of the conventional optical recording and reproducing apparatus will be mainly shown in FIG. 7 which includes an optical disc 1 with guide tracks being formed in the spiral shape therein, a disc motor 20 for rotating the optical disc at a normal speed, an optical head 103 which is adapted to linearly move in the diametral direction of the optical disc 1 by a stepping motor or a linear motor, a semiconductor laser 21 for transmitting the light transmission outputs in two front, rear directions, a condensing lens 22, a beam splitter 25, a tracking mirror 107, a focusing lens 23 which stops the light of the semiconductor laser 21 into the light of about 1 .mu.m in diameter on the optical disc 1, a first photdetector 109 which detects the reflection lights from the optical disc 1 to convert them into electric signals, a second photodetector 110 which converts, into electric signals, the monitor lights to be outputted from behind of the semiconductor laser 21, a pre-amplifier 111 which outputs as reproduction signals the variation in the quantity of the reflection lights from the optical disc, an integrator 112, a differential amplifier 113 for amplifying the difference between the output a.sub.o of this integrator 112 and a reference voltage b.sub.o to be preset by a variable resistor 114, the reference voltage b.sub.o being one for setting the oscillation level during the reproduction, for example, 1 mW, a sample holding circuit 115 which normally holds the output g.sub.o of the differential amplifier 113, a current supplying circuit (I) 116 outputs the current corresponding to the sampling value with the sample holding circuit 115 being switched from the sampling condition into the holding condition in accordance with the write gate signal, the current supplying circuit (I) 116 being adapted to drive the semiconductor laser 21 through a current adder 117, a level detecting circuit 120 which outputs such signals d.sub.o as the monitor signal corresponding to the record reproduction provided by the integrator 112 and the level j.sub.o to be set by a variable resistor 119 may become the 0 V of the "L" level of the TTL at the recording time and the 5 V of the "H" level of the TTL at the reproduction time by the use of the means of the comparator, a variable resistor 118 for setting the record power into, for example, 8 mW, a current supplying circuit (II) 122 which outputs the current i.sub.o necessary enough to output the record power into the semiconductor laser 21 corresponding to the voltage c.sub.o set by the variable resistor 118, a delay circuit for outputting the signal f.sub.o which has delayed by the use of the shift register the write gate signal e.sub.o of the terminal 121, AND circuits 125, 126, a D type flip-flop (hereinafter referred to as D-FF) constructed to be operated by the rising edge of the output of the AND 126, a CPU 128 for collectively controlling the optical recording and reproducing apparatus, and AND circuit 129 for controlling the write gate signal e.sub.o by the output of the D-F.F. 127, an analog switch 123 which is controlled with the gate signal m.sub.o, the output of the AND circuit 130 for inputting the data signal l of the terminal 131 and the write gate signal n.sub.o controlled by the AND 129, the analog switch 123 is adapted to turn on and off in accordance with the data signal only at the recording time, the current adder 117 adds the currents h.sub.o i.sub.i of the current supplying circuits (I) 116, (II) 122 to flow the added currents to drive the semiconductor laser 21.
The operation of the optical recording and reproducing apparatus constructed as described hereinabove will be described hereinafter with reference to FIG. 8.
The optical head 103 is moved into the given position of the optical disc 1 to output the beam lights from the semiconductor laser 21 so that the beam spot is stopped to 1 .mu.m or less in diameter on the optical disc 1 by the focus lens 23 through the collimator lens 22. At this time, the optical disc 1 rotates at a given speed by the disc motor 20, the beam light controls the tracking control along the guide track, detecting the guide track of the optical disc 1.
And the information recorded on the guide track of the optical disc 1 is added to a first photo detector 109 as variation in reflection factor and is converted into electric signals so that the reproduction signals are provided through the pre-amplifier 111. The reproduction time will be described hereinafter. The monitor lights from behind the semiconductor laser 21 are converted into the electric signals by a second photo detector 110, are amplified by the integrator 112, become the R portion of the signal a.sub.o shown in FIG. 8. The output is fed into the differential amplifier 113, which amplifies the difference between the signal a.sub.o and the reference voltage signal b.sub.o to be set by the variable resistor 114 to feed the signal g.sub.o corresponding to the difference to the sample holding circuit 115. At this reproduction time, the write gate signal n.sub.o of the output of the AND 129 is the "O" level, the sample holding circuit 115 is under the sampling condition. And the sample holding circuit 115 feeds the sampled value of the output signal g.sub.o of the differential amplifier 113 as it is into the current supplying circuit (I) 116. The current supplying circuit (I) 116 feeds to the semiconductor laser 21 through the current adder 117 the driving current h.sub.o corresponding to the R' portion of the output signal g.sub.o of the inputted difference amplifier 113. As the analog switching 123 is off at the reproduction time, the driving current i.sub.o of the other current adder 117 to drive the semiconductor laser 21 only with the driving current h.sub.o of the current supplying circuit (I) 116. The driving current waveform of the semiconductor laser 4 is shown in the K of FIG. 8. The output level of the beam light during the reproduction is controlled to a given value corresponding to the reference voltage b.sub.o by such operation as described hereinabove. Namely, during the reproduction, the operation is performed to stabilize the oscillation output with respect to the semiconductor laser 21.
The operation will be described hereinafter at the recording timing. The write gate signal n.sub.o of the output of the AND circuit 129 becomes the "1" level, the sample holding circuit 115 memories the input signal level of the R's of the output signal g.sub.o of the differential amplifier 113 immediately before it and become a hold condition. The held signal level R'.sub.H is supplied to the current supplying circuit (I) 116 to generate the current h.sub.H for driving the semiconductor laser immediately before the condition becomes a hold condition to addi it to the current adder. On the other hand, in order to record the information, the data signal l.sub.o of approximately 1 MHz through 2 MHz in frequency to the terminal 131 switches on, off the analog switch 123 through the AND circuit 130. Namely, when the data signal l.sub.o is "1" in level, the analog switch 123 becomes on, when the data signal "0" in level, the analog switch 123 becomes off. When the analog switch 123 is turned on, off by the data signal l.sub.o, the output current i of the current supplying circuit (II) 122 is added or is not added to the current adder 117, so that the current for driving the semiconductor laser 21 becomes the driving current of the h.sub.H or the driving current of the h.sub.H +i. Accordingly, the data bit corresponding to the data signal l.sub.o is formed in the guide track of the optical disc 1. At this time, the monitor light corresponding to the record beam light is inputted into the second photo detector 110. At this time, the output signal a.sub.o of the integrator 112 becomes high in level as shown in the W portion of FIG. 8.
The output a.sub.o of the integrator 112 becomes 0 V at the time of the record power, +5 V at the reproduction time as shown in the d.sub.o of FIG. 8 through the comparison between the voltage j.sub.o to be set by the variable resistor 119 and the level detecting circuit 120.
On the other hand, the write gate e.sub.o is delayed by the delay circuit 124 composed of the shift register, the signal e.sub.o for getting the f.sub.o in FIG. 8 and the f.sub.o are added to the AND circuit 125 so that the record optical power detecting section signal is provided for observing the record power delayed more than the original write gate e.sub.o of the terminal 121 as shown in FIG. 8, o.sub.o.
In the detecting section, the output of the level detecting circuit 120 is the 0 V of the "L" level of the TTL as shown in FIG. 8, d.sub.o. Thus, the output of the AND circuit 126 becomes normally the "L" level. The Q output p.sub.o becomes the "H" level with the D-F.F. 127 being not set, so that the output n.sub.o of the AND circuit 129 becomes equal to the write gate signal e.sub.o of the terminal 121. And the output n.sub.o of this AND circuit 129 is added to the AND circuit 130 to control the laser driving circuit.
When the output d.sub.o of the level detecting circuit 120 does not become the record optical power because of the breakdown of the semiconductor laser or the disorder of the semiconductor laser driving circuit during the record light power detecting section of the output of the AND circuit 125, the output a.sub.o of the integration amplifier 112 is provided as in FIG. 8, a'.sub.o. Thus, the output d.sub.o of the level detecting circuit 120 becomes also +5 V which is the "H" level of the TTL despite the recording time as in FIG. 8, a'.sub.o. Thus, the output d.sub.o of the level detecting circuit 120 becomes also +5 V which is the "H" level of the TTL despite the recording time as in FIG. 8, d'.sub.o. At time time, the D-F.F. 127 is set, the output p.sub.o of the Q becomes the "L" level from the record power breakdown. The original write gate e.sub.o of the terminal 121 is forced to close by the AND circuit 129 as shown in FIG. 8 n'.sub.o. Namely, this is a light fort function. A write protecting circuit 132 is composed of the delay circuit 124, the AND circuits 125, 126, 129 and the D-F.F. 127. When the write protecting function works, the Q output p'.sub. o of the D-F.F. 127 is added to the interruption input which is the input port of the CPU 128, so that the CPU 128 recognizes this abnormal condition. And the CPU 128 performs its abort processing operation to report through the interface that the light fort has been caused in the host during the processing operation. Finally the CPU 128 clears the D-F.F. 127 by the outport of the CPU 128 to complete a series of processing operations.
However, such conventional construction as described hereinabove had a problem that the data the user tries to save in this record reproducing apparatus was required to be removed when the write protector did not function for some reasons.
Accordingly, an object of the present invention is to provide an optical recording and reproducing apparatus, wherein this positive operation of this function may be recognized in the processing of the diagnosis.
The processing operation will be described hereinafter in a case where the disc motor for rotating the optical disc has been wrong during the recording operation.
In the optical recording and photorecord reproducing apparatus, it is important to record at the normal rotation speed on the track of the disc through the rotation of the disc at the normal rotation speed when the information is recorded on the disc.
Referring now to the drawings, there is shown in FIG. 10, an optical and reproducing apparatus with the motor driving portion and the recording portion as the main units, which includes an optical disc 1 with the guide track being spirally formed, a disc motor 20 for rotating the optical disc at the normal speed, an optical head 103 which is adapted to be linearly driven in the diametrical direction of the optical disc 1 by a stepping motor or a linear motor not shown, a semiconductor laser 21 for transmitting the light emitting output in two front, rear directions, a focus lens 22, a beam splitter 25, a tracking mirror 107, a diaphragm lens 23 which focuses the light of the semiconductor laser 21 into the light of about 1.mu.m in diameter on the optical disc 1, a first photo detector 109 which detects the reflection lights coming from the optical disc 1 to convert them into electric signals, a second photo detector which converts into the electric signals the monitor lights to be outputted from behind the semiconductor laser 21, a pre-amplifier 111 which may output the variation in the reflection light quantity from the optical disc as the reproduction signals, a current supply circuit (I) 116 which causes the current of the semiconductor laser driving operation at the reproduction time, a variable resistor 114 which sets to, for example, 1 mW the optical power to be outputted from the optical head during the reproduction, a current supply circuit (II) 122 for producing the current of the semiconductor laser driving operation during the recording operation, a variable resistor 118 which is adapted to set to, for example, 8 mW the optical power to be outputted from the optical head during the recording time, an analog switch 123 which are controlled by the gate signals that are outputs of the AND circuit 219 with the data signal l.sub.o of the terminal 131 and the write gate signal e.sub.o of the terminal 121 as outputs, the analog switch 123 is turned on and off in accordance with the data signal only during the recording operation, a current adder 117 adds the currents h.sub.2, i.sub.2 of the current supply circuits (I) 116, (II) 122 to flow the added current to drive the semiconductor laser 21, a motor driving circuit 221 for driving the disc motor 20, a motor synchronism detecting circuit 222 for detecting whether or not the disc motor 20 is operated at the normal rotation speed, a CPU 128 which turns on, off the disk motor 20, and controls the entire optical recording and reproducing apparatus.
The operation of the optical recording and reproducing apparatus constructed as described hereinabove will as described hereinabove.
When the optical disc 1 is engaged on the disc motor 20, the CPU 128 outputs the motor start signals from the outport (1) into the motor driving circuit 221. The motor driving circuit 221 rotates the disc motor 20. When the disc motor 20 becomes the normal revolution number, the motor synchronism detecting circuit 222 detects it to add the motor synchronism signal f.sub.2 to the import (1) of the CPU 128 to notify the CPU 128 of the correct motor synchronization. The CPU 128 moves the optical head 103 to the given position of the optical disc 1.
The beam light is outputted from the semiconductor laser 21 to focus the beam spot to 1 .mu.m or lower in diameter on the optical disc 1 by the focus lens through the condenser 22. At this time, the optical disc 1 is rotated at a given speed by the disc motor 20, the beam light performs the tracking controls along the guide track, detecting the guide track of the optical disc 1.
And the information recorded on the guide track of the optical disc 1 is added onto the first photo detector 109 as changes in the reflection factor and is converted into electric signals so that the reproducing signals are provided through the pre-amplifier 111. The operation about the reproduction will be described hereinafter. The monitor light coming from behind the semiconductor laser 21 is converted into the electric signals by the second photo detector 110 and is added to the current supplying circuit (I). The current supplying circuit (I) stably controls the oscillation output of the semiconductor laser 21 independently of the temperature or the like through the reference voltage to be set by the variable resistor 114 to apply upon the current adder 17 the current c.sub.2 where the optical power, during the reproduction of, for example, 1 mW is normally applied upon the optical disc. As the analog SW 123 is normally off during the reproduction time, the current d.sub.2 of the other current supplying circuit (II) 122 is driven by the semiconductor laser 21 only through the current c.sub.2 of the current supplying circuit (I) 116 without applying upon the current adder 117.
The operation during the recording operation will be described hereinafter. First, the write gate signal e.sub.o of the terminal 18 becomes "1" level, the current supplying circuit (I) 116 samples the control voltage equivalent to the current c.sub.2 just prior to it to hold the control voltage. While the write gate signal b is "1", he current C.sub.H corresponding to the control voltage held is normally held into the current adder 117. On the other hand, to record the information, the data signal a of about 1 MHz through 2 MHz in frequency to the terminal turns on, off the analog switch 123 through the AND circuit 219. Namely, the analog switch 123 is turned into the ON condition when the data signal l.sub.o is "1" level, the analog switch 123 is turned into the OFF condition when the data signal l.sub.o is "0" evel. The analog switch 123 is turned on, off by the data signal l.sub.o to apply the output current d.sub.2 of the current supplying circuit (II) upon the current adder 117 or not to apply the output current upon it, so that the current k.sub.2 for driving the semiconductor laser 21 becomes the driving current of C.sub.H or C.sub.H +d.sub.2 as shown in FIG. 3.
Accordingly, data bits corresponding to the data signal 131 are formed upon the guide track of the optical disc 1.
In this case, it is important to know whether or not the information is positively recorded on the disc. Thus, when the information is recorded in the disc, it is demanded that the disc should be normally rotated to record the record data at the normal pit length. Therefore, it is demanded to protect the user data through the immediate compulsory suspension of the recording operation to notify the user of it for the aborting operation when the disc has not been correctly rotated during the recording operation. Also, it is important for the user himself to previously know the positive operation of the write protective function, which is adapted to compulsorily stop the recording operation.
The present invention is an optical recording and reproducing apparatus comprising means for detecting the track jumping by the track crossing signal, a write protecting means which reduces the optical power from the record power to the reproduction power by the track jump detecting means, a diagnostic means for confirming whether or not the track jump detecting means and the write protecting means normally operate.
The artificial write gate is caused at the resetting time or the like of the apparatus by such construction to cause the track crossing signal through the starting operation of the track jump during the artificial write gate production period, the diagnosis is performed to confirm the correct operation of the track jump detecting means and the lighting means to positively prevent the error record, the double record to be caused by the track jump.
Also, the present invention is an optical recording and reproducing apparatus comprising means for monitoring the optical power, write protecting means which compulsorily prohibit the record when the light monitor signal is not detected as the recording condition at the recording time, means for artificially generating the write gate signals during the diagnostic, means for confirming whether or not the write protection operated. The light power performs the diagnosis, by such construction as described hereinabove, during the reproduction, the CPU which is an artificial write gate signal generating means artificially outputs the write gate signal when the detection signal of the power monitor means becomes a reproducing condition at this time. When the signal has been outputted, the write protecting means function. And the CPU confirms that the write protecting means has functioned.
Furthermore, the present invention is an optical recording and reproducing apparatus comprising a disc motor driving means, a motor synchronism detecting means of the disc motor, a means for recording the information on the disc, a write protecting means which compulsorily prohibit the record operation when something has been wrong during the recording operation, a means to externally notify that the write protecting means has operated. Also, the present invention is an optical recording and reproducing apparatus comprising a means which artificially turns the condition into the recording condition during the diagnosis, a means which intentionally turns the motor synchronizing signal into the signal to be equivalent to the abnormal time. When the rotation of the disc motor which rotates the disc during the recording operation has become abnormal, the write protecting function operates to perform the compulsory prohibition in accordance with such construction. Also, in the present invention, the condition is artificially kept on record condition when the motor synchronizing signal is normal in the diagnosis. Furthermore, the motor synchronizing signal is intentionally made abnormal by the suspension of the disc motor driving operation. At this time, it is confirmed that the write protecting function has functioned.